Somatic embryogenesis and plant regeneration from protoplasts of Cichorium intybus L. x Cichorium endivia L.

Abstract

Somatic embryos and adult plants were regenerated from mesophyll protoplasts of a clone of chicory '474' (Cichorium intybus L. x Cichorium endivia L.). Embryos were obtained in three different ways: -plating of 7-day-old protoplast cultures on PM-3 solid induction medium with 2.5 IxM 2-isopentenyladenine (2-iP) and 0.5 I~M naphthaleneacetic acid (NAA); -transfer of 1-2 mm microcolonies into liquid M-17 induction medium with 2.5 ixM (2-iP) and 0.1 ixM (NAA); -transfer of well-established protoplast-derived calluses onto M-17. Development of embryos was accomplished in agitated liquid Heller medium with 0.15 t~M gibberellic acid and germination on solid Heller medium without growth regulators. The total time for plantlet (4-1eaves stage) recovery, following protoplast isolation, was 13 to 15 weeks. After acclimatization all protoplast-derived plants of Cichorium '474' were phenotypically normal and fertile.

Cellular Markers for Somatic Embryogenesis

“…The analysis of the presence of plasmodesmata in the callus cells of Cichorium shows the disappearance of connection by plasmodesmata during somatic embryogenesis, indicating that cells which will undergo new a physiological state are isolated from their neighbouring cells (Sidikou-Seyni et al, 1992). Similar results were described in the case of grasses, where the plasmodesmata connection existed only between cells belonging to the same group of cells creating aggregates (Karlsson & Vasil, 1986).…”